[PATCH v4 1/4] Bluetooth: hci_bcm: Disallow set_baudrate for BCM4354

From: Abhishek Pandit-Subedi
Date: Tue Nov 12 2019 - 18:10:15 EST


Without updating the patchram, the BCM4354 does not support a higher
operating speed. The normal bcm_setup follows the correct order
(init_speed, patchram and then oper_speed) but the serdev driver will
set the operating speed before calling the hu->setup function. Thus,
for the BCM4354, disallow setting the operating speed before patchram.
If set_baudrate is called before setup, it will return -EBUSY.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
---

Changes in v4: None
Changes in v3: None
Changes in v2: None

drivers/bluetooth/hci_bcm.c | 37 ++++++++++++++++++++++++++++++++++++-
1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 0f851c0dde7f..6134bff58748 100644
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -47,6 +47,14 @@

#define BCM_NUM_SUPPLIES 2

+/**
+ * struct bcm_device_data - device specific data
+ * @no_early_set_baudrate: Disallow set baudrate before driver setup()
+ */
+struct bcm_device_data {
+ bool no_early_set_baudrate;
+};
+
/**
* struct bcm_device - device driver resources
* @serdev_hu: HCI UART controller struct
@@ -79,6 +87,7 @@
* @hu: pointer to HCI UART controller struct,
* used to disable flow control during runtime suspend and system sleep
* @is_suspended: whether flow control is currently disabled
+ * @disallow_set_baudrate: don't allow set_baudrate
*/
struct bcm_device {
/* Must be the first member, hci_serdev.c expects this. */
@@ -112,6 +121,7 @@ struct bcm_device {
struct hci_uart *hu;
bool is_suspended;
#endif
+ bool disallow_set_baudrate;
};

/* generic bcm uart resources */
@@ -141,9 +151,13 @@ static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed)
static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed)
{
struct hci_dev *hdev = hu->hdev;
+ struct bcm_data *bcm = hu->priv;
struct sk_buff *skb;
struct bcm_update_uart_baud_rate param;

+ if (bcm && bcm->dev && bcm->dev->disallow_set_baudrate)
+ return -EBUSY;
+
if (speed > 3000000) {
struct bcm_write_uart_clock_setting clock;

@@ -551,6 +565,12 @@ static int bcm_setup(struct hci_uart *hu)
goto finalize;
}

+ /* If we disallow early set baudrate, we can re-enable it now that
+ * patchram is done
+ */
+ if (bcm->dev && bcm->dev->disallow_set_baudrate)
+ bcm->dev->disallow_set_baudrate = false;
+
/* Init speed if any */
if (hu->init_speed)
speed = hu->init_speed;
@@ -1371,6 +1391,15 @@ static struct platform_driver bcm_driver = {
},
};

+static void bcm_configure_device_data(struct bcm_device *bdev)
+{
+ const struct bcm_device_data *data = device_get_match_data(bdev->dev);
+
+ if (data) {
+ bdev->disallow_set_baudrate = data->no_early_set_baudrate;
+ }
+}
+
static int bcm_serdev_probe(struct serdev_device *serdev)
{
struct bcm_device *bcmdev;
@@ -1408,6 +1437,8 @@ static int bcm_serdev_probe(struct serdev_device *serdev)
if (err)
dev_err(&serdev->dev, "Failed to power down\n");

+ bcm_configure_device_data(bcmdev);
+
return hci_uart_register_device(&bcmdev->serdev_hu, &bcm_proto);
}

@@ -1419,12 +1450,16 @@ static void bcm_serdev_remove(struct serdev_device *serdev)
}

#ifdef CONFIG_OF
+struct bcm_device_data bcm4354_device_data = {
+ .no_early_set_baudrate = true,
+};
+
static const struct of_device_id bcm_bluetooth_of_match[] = {
{ .compatible = "brcm,bcm20702a1" },
{ .compatible = "brcm,bcm4345c5" },
{ .compatible = "brcm,bcm4330-bt" },
{ .compatible = "brcm,bcm43438-bt" },
- { .compatible = "brcm,bcm43540-bt" },
+ { .compatible = "brcm,bcm43540-bt", .data = &bcm4354_device_data },
{ },
};
MODULE_DEVICE_TABLE(of, bcm_bluetooth_of_match);
--
2.24.0.rc1.363.gb1bccd3e3d-goog